Electronic Workbench Tool Organiser Part 2 - Power Supply

In the part 1 of this instrucatble, a design for a tool holder with rest for meters was shown. This instructable expands on that to provide a general purpose power supply with additional holders.

Main features added are

1. Mains socket
2. Switched variable power supply with current limiting
3. Switched 5V supply
4. USB 5V supplies
5. Switched 12V supply
6. LED on/off switches and displays
7. Test cable hangers

The description assumes that the original organiser has already been made and is now being modified with the power supply, but the idea could be adapted to many other designs.

IEC socket, fused and switched

IEC lead, with mains connection plug suitable for the locality.

Switched mode 12V power supply

ZK-4KX variable power module

6 x binding posts ( I chose 3 x black and three different colours for the different supplies)

4-socket USB module

2 x cheap 12V power switches, I used these with in-built LEDs

12V 40mm fan (optional ventilation)

Screw terminals, small piece of strip board. 5 x doubles and one triple block used.

9 x spade connectors and insulators

6 x ring terminals

shrink wrap if required

3D printed parts available on TinkerCAD here and here

Remove the front panel and test fit the power unit to be fitted to ensure that it does fit in the space.

This step is best done with the rear panel of the organiser removed.

Taking the measurement from the PSU being used, 15cm from the edge, mark a rectangle to be cut out to accommodate the socket. Drill approximately 10mm holes to allow the easy use of a jigsaw to cut out the hole and then make the cuts. Test fit the socket and fine trim the hole until it is a good fit. Screw the socket in place.

The close-up picture of the rear of the socket shows the wiring.

Before refitting the rear of the organiser, connect the PSU to the inlet socket as well as any supply leads to be used, two are shown here. Once connected, refit the rear panel.

Fit a screw into place which allows the PSU to be slid into place and secured. It may be difficult to access this screw after the PSU is in place. Slide the PSU into place and secure with another screw, having first ensured that the PSU case does not foul the front panel of the organiser when it is refitted.

In this step a box is made to fit under the organiser shelf to contain the console electronics. Two strips of wood were cut the same width as the original, in this case 40cm, one 6cm wide as a lid, and one 35mm wide as a lower side. Also two other pieces were cut as end cheeks to fit, again with this wood it was 42mm wide by 35mm high.

The two end cheeks were glued and clamped in place until set. The lid was screwed to the lower side and the lower side was then glued in place and clamped, taking care not to get glue on the lid.

The front panel was made up of a selection of 3D printed front panels so that a suitable arrangement could be designed and easily rearranged as desired. The selection is shown in the pictures and is available on TinkerCAD here. .stl files can be downloaded from the final step.

There are two versions of the variable power supply module panel, one with and one without binding hole mounts so that the builder has a choice.

A two hole binding post panel

A single switch panel

A USB module panel

A 40mm fan module. This is a grill with mounting hole for the fan.

All panel pieces have mounting holes to attach them to the console.

Here there's a deviation from basic woodworking to add a 3D printed front panel. It isn't essential, I've added it because it guarantees a neater edge, but if your wood cutting skill is up to it then you'll be able to cut the holes perfectly.

I used the 3D printed part as a template to mark out the hole to cut, but the file attached can be used to print a paper template which would help cut the holes.

To facilitate ventilation and cable routing, slots have been cut in the front panel behind the console and a small piece removed from the internal support to prevent cable fouling

There are a few independent power cables providing ground and 12V to the front panel. A small piece of matrix board has been fitted with screw terminals with additional thick copper wire to improve conductivity. A separate double connection point is added to allow connection of a ventilation fan if required.

The first picture shows the rear of the panel ready for wiring. 17A automotive wire cabling was used because I had it left over from stripping out another project. It was cut into 200mm (8") lengths to make it easy to handle and then ring terminals and spade connectors were attached to the ends appropriately.

When complete, the individual supplies and modules were tested.

The ventilation fan is optional and in this case had been removed from some salvaged equipment. It has been mounted in an end cheek with a 3D printed fan cover.

It is expected that air drawn into the organiser by this fan will pass over the modules before being vented at the other end of the organiser.

The wires from the console were wired to the power distribution board first. The front panel was then introduced to the main organiser so that the fan and power supply could be attached. The front panel was then reattached but only fitting the top three screws, the others are inside the console box.

With the front panel attached, the console was unscrewed and the remaining screws inserted and tightened, making sure all the cables routed safely. Once attached , the console was reattached.

To keep test wires organised, two holders were designed and made. One is a simple holder wire the wires are long and can be draped over, the other is for small dupont connectors which can be held by slotting them into the comb. The design for both is on TinkerCad here or available as an .stl in the final step.

The purpose of these changes to to continue the theme of decluttering my workbench while keeping functionality easily available. I haven't done it yet, but next I'm thinking of screwing a multimeter to the organiser with a permanent isolated power supply to be more easily available. If I do I'll write another instructable.

Attached here, because they would otherwise clutter up the article, are the .stl files for the console and the wire holders.